• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.205-211
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• 2005

Turnkey projects accounting for some $10\%$ of the total volume of the projects in the domestic market have been often implemented without the process of full-scale review or study because of clients' lack of expert and expertise. Moreover, many projects have been executed under the terms and conditions of the contact which were found to be unilaterally in favor of the clients. The study, as part of effects to mitigate the claims that would possibly be caused by the potential problems with the typical turnkey projects, were intended to identify the elements of the claims virtually being occurred at the construction sites, and then analyze the degree of influence on the project so as to be able to incorporate the outcome into the plan at the working-levels. As a result of experts' review, through the survey, of the elements once extracted, those having relatively higher degrees of influence on turnkey projects were determined, and the investigation aimed at estimating the amount of claims in terms of value were conducted to eventually identify, evaluate and verify the elements that had affected the Project together with the degree of influence.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.598-610
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• 2022

Avoiding a fault zone would be a best practice for safety in underground construction, which is only sometimes possible because of many restrictions and other field conditions. For instance, there is an ongoing conception of Korea-Japan subsea tunnels that inevitably cross a massive fault system in the Korea Strait. Therefore it was deemed necessary to find an efficient way of predicting the likely behaviour of underground structures under fault slip. This paper presents the findings from simple numerical analysis for investigating the stress induced at a normal fault with a dip of 45 degrees. We used a boundary element software that assumed constant displacement discontinuity, which allowed the displacement to be estimated separately at both the fault's hangingwall and footwall sides. The results suggested that a principal stress rotation of 45 degrees occurred at the edges of the fault during the slip, which was in agreement with the phenomenon for fault plane suggested in the body of literature. A simple numerical procedure presented in this paper could be adopted to investigate other fault-related issues associated with underground structure construction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3D
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• pp.353-359
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• 2006

Image frame analysis is a conventional way of evaluating loop detector's performance. In image frame analysis, the time to evaluate performance is linearly proportional to the number of evaluated subjects, and the results can be subjective, depending on operator's personal evaluation standards and physical condition. Also, this method is often inferior in accuracy to that provided by the evaluated devices. Therefore, it is critical to develop a portable standard system which has better accuracy and more objectivity in evaluating vehicle detectors. This paper discusses function and reliability of tape-switch detector, which can be a replacement for image frame analysis, for effectively measuring traffic volume, speed, and occupancy.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.1
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• pp.10-19
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• 1992

서해안 시대를 맞이하여 21세기를 열어나갈 새萬金 千拓綜合開發事業 기공식이 지난해 11월 28일 전북 부안군 변산면 대항리 현장에서 盧泰愚대통령, 曺京植농림수산부장관, 金榮鎭農漁村振興公私社長, 국회농림수산위원회 위원장, 전북도지사, 地域出身國會議員등 내외 귀빈과 지역 주민 2,400여명이 참석한 가운데 열려 사상 최대의 간척사업으로서 첫발을 내딛었다. 이날 盧泰愚대통령은 치사를 통해 "자손만대에 물려줄 웅대한 국토확장의 첫삽을 뜨게 되어 깊은 감회를 느낀다"면서 "만경, 김제의 넓은 벌이 우리나라의 곡창으로 겨레의 삶을 보장해온 터전이었듯이 새만금의 광활한 간척지를 21세기 번영을 기약하는 땅이 되도록 하자"고 당부하였다. 새만금사업의 공사기간은 '91년부터 98년까지 외곽방조제를 완공하고 2004년까지 내부개발을 완료할 예정이고, 총 사업비 1조 3천억원을 투입하게된다. 사업지역은 1도 3군 1시 19읍면동 (전북 옥구군, 부안군, 김제군, 군산시)에 걸쳐서 40,100ha를 개발하게 된다. 주요시설로는 부안군 변산면 대항리에서 可力島, 新侍島, 夜味島, 및 飛鷹島를 연결하는 세계 최장의 방조제 33km를 축조하고 방조제 위에는 4차선 도로를 설치하고 장항선이 군산하구둑을 경유, 이 방조제를 거쳐 고군산군도까지 갈 수 있도록 하는 철도부지도 건설된다. 이와 함께 새만금국제항을 개설, 연간 5,000만톤의 하역능력을 갖게 되고 고군산군도를 잇는 관광휴양지가 형성된다.

• Proceedings of the KSEE Conference
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• 2008.10a
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• pp.17-28
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• 2008

국책사업이나 SOC의 확충을 위한 도로 및 철도의 건설에서 적용되는 터널의 단면크기를 보면, $50m^2$에서부터 $100m^2$이상의 중 대단면 터널이 주를 이루고 있으나, 전력구, 통신구, 소규모로 운영되는 광산의 채광용 터널, 용수를 위한 도수로터널 등 특수한 용도로 설계, 시공되고 있는 터널에서는 $20m^2$이하의 단면크기를 갖는 경우가 있다. 이러한 소단면 터널의 경우에는 협소한 작업공간으로 인하여 적용공법 뿐만 아니라 장비의 사용 또한 제약을 받게 되어 작업효율이 저하되고 공사기간이 늘어나게 되는 등 여러 가지 문제점을 안고 있다. 특히, 에멀젼 폭약을 사용하는 발파에서 먼저 기폭된 발파공의 충격압력에 의해 인접공의 폭약이 예비압축(Precompression)되어 사압현상을 일으키고 잔류약을 발생시키는 사례가 종종 발생하고 있다. 사압현상은 당해 발파의 실패와 함께 2차적인 사고의 위험요인이 될 수 있으므로 이를 방지하기 위한 대책을 수립하여야 한다. 이를 위해 기존 문헌을 통하여 사압현상의 원인과 발생 가능성을 검토하였고, 국내에서 주로 사용되는 에멀전폭약의 수중 내충격성시험과 충격압력 전달시험을 실시하여 사압현상의 발생정도를 측정하였으며, 사압현상이 발생한 소단면 터널현장을 대상으로 대책을 수립하여 적용하였다. 심발방법을 변경하여 전단의 충격압력을 견딜 수 있는 공간격을 확보하고 뇌관의 초시간격을 적절하게 배치한 발파패턴을 적용한결과, 사압현상을 억제하고 잔류약의 발생을 감소시켜 계획 굴진장을 확보하고 파쇄석의 크기를 감소시키는 등 양호한 결과를 얻을 수 있었다.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.497-504
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• 2020

In Korea construction industry, researches are being conducted to reduce the disasters related tower crane due to the increase of tower crane's usage and accidents continuously. Although the usage amount of remote control tower crane has been increasing recently, the research on remote-control tower crane is insufficient. In this study, the importance ranking of remote control tower crane's accident factors derived by AHP analysis. AHP questionnaire was conducted to engineers (or operators) like construction site engineer, construction manager, safety engineer, and tower crane operator, who have more than 10 years career. The results of AHP analysis reveal that top ranking factor of remote control tower crane's accident is lifting work for materials. Therefore, the high importance factors should be managed, and taken the priority measures for reducing the tower crane accidents by using the results of this research.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.961-964
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• 2008

There are researches in progress on ensuring the safety of the high impact concrete in case of fire which is a current rising social problem and this research institute also developed PFB technology, the explosion preventing technology. PFB technology is to apply POSCO E&C Fire Board, a fireproof board, with an adhesive agent on the construction site, and this technology passed 3-hour fireproof test and this technology was proven from a previous research that the temperature of main root is maintained under $200^{\circ}C$. Therefore, tests on basic contents was performed in this research before the actual construction, with a full scale of wooden prototype to apply PFB technology to actual construction sites and the tests were done on the workability of fireproof board, the adhesive power, the resistance against imprint of wooden nail, the heat conductivity and etc. As the results of these tests, PFB technology was proven to have an excellent workability at a construction site and to be easy for processing and also, this technology was proven to have a great resisting power against imprint of wooden nail. Therefore, this research has confirmed that PFB technology has no problem to be applied on a construction site.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.232-239
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• 2001

Young Jong Grand Bridge is approach traffic road of New Inchon International Airport which covers hub airport function in northeast asia. The total span length of this bridge is $4,420{\cal}m$ and this main bridge type is, the first in the world, Double Deck Self Anchored Suspension Bridge, designed as double deck systems to be arranged by road and railroad. Approach bridges to be connected with main span also are composed double deck steel truss and steel box girder to consider a continuity with this span. Our company erected $1,375{\cal}m$(about 60,000tons) of double deck steel truss bridge type which is composed by 6 traffic lane on upper deck and 4 traffic lane and Double track railroad on lower deck. The original installation method of this bridge was planed to install about 75 meters bridge blocks to use floating crane, after temporary bent was constructed between permanent piers. But this method which had to construct many temporary bents in the sea had the matter that construction periods can become lengthen and construction cost can be risen. To overcome the uncertainty to ensure high qualify of bridge and economic project execution, our company developed new bridge erection method to assure both quality control and economic construction work. The new erection method which was developed by us was one that could transport and install long bridge block, $120{\cal}m$ unit at a time and that temporary bent was not required. We hope that this paper is used as technical data which will erect bridge in the western sea and others marine region.

• Journal of the Korean GEO-environmental Society
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• v.23 no.8
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• pp.11-16
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• 2022

The compaction process using vibrating rollers in road construction is essential to increase soil stiffness in earthworks. Currently, there is no clear standard for the operation method of the compaction roller during compaction. Although simple quality inspection techniques have been developed, plate load test (PLT) and field density test (FDT) are the most frequently used test methods to evaluate the degree of compaction during road construction as the most frequently used quality inspection methods. However, both inspection methods are inefficient because they cannot perform quality inspection in all sections due to time and cost reasons. In this study, we analyzed how the operating conditions of vibrating rollers affect the compaction quality. An intelligent quality management system, which is a currently developed and commercialized technology, was used to obtain quality inspection results in all sections. As a result of the test, it was analyzed that the speed and vibration direction of the compaction roller had an effect on the compaction degree, and it was found that the compaction direction had no effect on the compaction degree.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.47-54
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• 2013

This study is the basic research to develop the customized base module for modular road system. A case study was carried out on designs of base module for soft soil condition. Two types of base module was proposed; crossbeam module and crossbeam-pile module. Based on the case study, it was verified crossbeam-pile module is suitable for soft soil condition and the optimum dimension of crossbeam-pile module for modular road system constructed on soft soil was determined. For development of the optimal base modular for modular road system, it is needed in the future to build a data base about ground and roadbed of road construction sites and to classify and systemized base modules according to soil conditions through many case studies.